Process for fluosulfonic acid refining of lubricating oil



Jan. 16, 1951 P. H. cARNELL PROCESS FOR FLUosULFoNIc ACID REFINING oF LUBRICATING on. Filed Dec. l5, 1947 Ilwx.

uNn yNolwesfda's R Am C Hf LM S, w. m m l A Patented Jan. 16, 12,951

UNITEDg STATES PATENT OFFICE PROCESS Fon FLUosUI'JFoNIo ACID REFINING `or LUBRICATING `OIL Paul H. Carnell, Alma, Mich., assigner to Phillips Petroleum Company, a corporation of Delaware Application December- 15, mit, serial No. 191,804

l This invention relates to the treatment of lubricating oils to improve their properties. In one of its more specic aspects it relates to treatment of a lubricating oil to improve its viscosity index. '-7 I have discovered that treatment of a lubricating oil with iiuosulfonic acid, and if desired, a low-boiling hydrocarbon, such as, isoor normal pentane, will improve the viscosity index of the oil. l

Lubricating oil referred to herein, includes all such products and their base stocksv which have a viscosity Within the range of about 32 SUS (Saybolt Universal Seconds) at 210 F. toabout 350 SUS at 210 F., and as are usually understood to be covered by this term by those skilled in the' art. Ity includes lubricating oil stocks, such as, parain-base stock, naphthene-basefs'tock. synthetic-base stock, and mixed-base stock, which are rened for use as engine lubricants.

The important improvement in oils treated by the present process is in the viscosity index which is determined by the method describedin the article entitled Viscosity Variations -of Oils'with" Temperatures," by E. W. Dean and G.H.G. Davis, in Chemical and Metallurgical Engineering, volume 36, pp. 619 (1929). The viscosity index of a lubricating oil is an indication of its composition or type, i. e., whether it is a lp,araiiin-loase or'naphthene-base oil. Paraihn-base oils have high viscosity indices,- naphthene-ba'gse oils have relatively low viscosity indices, and'fmixed-base oils have viscosity indices betweenmtlfiesey two. This index is likewise a measure of the ability of a lubricating oil to remain viscous at high temperatures. As is well known, oils lose their viscosity rapidly with an increasejn temperature. The oil with a high viscosity index will, however, lose its viscosity less rapidly than an oil with a low viscosity index when-the temperature in increased, or conversely, will'not have its viscosity unduly increased by a lowering of temperature. The present invention increases this viscosity index.

I have discovered that uo'sulfo'nic acid (HSYOaF) vis an excellent refining agent for lubricating oils. Further, I have fou difthat, under suitable reaction conditions, this acid is superior to hydrofluoric acid in. producing high viscosity index oils. Also in the processing Yovfjertain lubricating oils, particularly mixed-bas'enoils, fluosulfonic acid treating yields higher viscosity indices than treating with sulfuric acid A"under similar conditions. An object of the present invention is to provide a method for improving lubricating oils. An-

other object is to provide a methodv for improv? In accordance with this invention lubricating oil is treated with fluosulfonic acid to improve its viscosity index. This process is operated at temperatures within the range of about l0 to about 60 C., at about atmospheric pressure, and for a. period of about to about 120 minutes. If dey sired, a low-boiling hydrocarbon, such as iso- Vor point in the fractionatio normal` pentane may-be vadded to the lubricating oil-uosulfonic acid mixture to aid in breaking theoil out 4of the acid, particularly when a large. volume of acid is used. In commercial operationv of-.this invention, the relative amounts of oil and acid used may vary considerably depending upon the extent of vrefining desired, however, it is genf erally preferred to use an acid to oil volume ratio inlthe range of about 0.5,.: 1 to about 2:1. A better understanding of my invention may -be hadby referring to the'attached schematic flow diagram.

Into reactor I0, are introduced isopentane,l 1 u-' bricating oil, and iiuosulfonic acid through lines 11, l2, and 13, respectively, where they are contacted for a period of about 15 to about 120 minutes at a temperature in the range of about 10 to about C. and at suilicient pressure to maintain liquid phase. Etiluent from reactor I0 is removed through line I'lI to settler I5 where it is separated into two phases, an oil phase, and an acid phase. The oil phase is removed from settler I5 through line I6 to separation unit I1. In separation unit I1 isopentane, or whatever low-boiling hydrocarbon has been employed in the previous treatment, is removed through line I8 for recycle through line II tg reactor I0. Hydrocarbons boiling below the initial boiling point of the untreated oil are removed through line I 9. Lubricating oil is removed through line 20 and may be subjected to other treatment, as desired, such as being caustic washedifand/or clay treated. In some instances, it maygbe desirable to caustic Wash the oil phase before or at an intermediate Any heavier material is discharged through e fe 26. From settler I5, a uosulfonic acid phasejis removed through line 2|. A portion may be recycled through line 25.

In three separate runs, a mixed-, baselubricat; ing oil, diluted with isopentane Wasftreatedwith: .l

hydrofiuoric acid, sulfuric acid, and "fluosulfnic/ acid at about room temperature.' vfor?arperiodv ofiA (Addition of the iluosulfo'nicracid'to;y

60 minutes. the lubricating oil-isopentane,mixtureproduced some temperature rise.)

Tire" volume ratidof 011' 4 in the presence of a low-boiling hydrocarbon for a period of about 15 to about 120 minutes, at a temperature in the range of about 10 to about 60 C. and at sufficient pressure to maintain liquidphase, using a volume ratio of said uoofr the process.

l 2.,A.processfor. rening a lubricating oil to improve-itsviscosity index, which comprises treating a' lubricating oil With fluosulfonic acid as the onlytreating'agentin the presence of a low-boilfin-gv. hydrocarbon, separatingr said oil-acid-lowboiling hydrocarbon mixture into an oil phase and a fluosulfonic acid phase, and recovering a to acid to isopentane was about 1:1:1. The acidgjj and oil layers were separated and the oil caustic washed and topped. .to-the.initiallboiling point ,ofthe untreated oil in "a -vacuurnviractionatingl col# ux'nn 'to-remove l'ght'ends.

The ,following physical data Werefvdetermlned'f fflr.r the product oils; -4 l .l Run 2..4

A*-l1`orlv1 a compars'on'of-the data from-run '311 which represents the treatmentfof 'lubricatingv oil-A vvith iluosulfonic acidj'w'ith thedatagfrom-runs'1`A and 2f;- vit may Ibe seen that the' luosulfonic iacid" treatmentof lubricating oil is'l rsuperior toA that' of Eydrolu'oric acid or sulfuric acid; in'that tl'iervis-N csity index is increased by'15 points, from-850i' theo'riginal'oil to 100'. f" "5 Although this;'inventionhas'been describedand" exernplied in terms of'itsA piufe'rred''m0:Iiica"- tions, it is runderstood-th'at various: cha'ngesmayAv l b'emade VWithout departingr from ith'e-spiritof the' process as disclosed and expressed in the claims."

I aim: Y I

11=A process for refining a lubricating oil to` improve its viscosity index, which comprises-` treating lubricating oilwith fluosulfonc'acida lubricating oil of improved viscosity index as a product of the processi;

3 A process for improvinga lubricatingI -oil v vhichzcomprisestreating a lubricating oil with; uosulfonicacid as the only treating agent in the,y presence of a low-boiling hydrocarbon, recovering-' 4 an improved lubricating oil as a productlof -the process.v 1 ;1 4; A .processior rening ,a lubricating-,oil :tovim proveits viscosity index, which comprises treat?V ing a lubricating oil with iluosulfonic acid fora@ periodof aboutzl to about '1.20. minutes, at a temi perature inthe rangeof about vloto about SOSC and fat suflicient.. pressureI to. maintainl liq'uid' phase,-lusingfa volume ratio of said iluosulfonica acid "to" oil about 0.5:1 to 2:1, separating said `ail.. acid mixtureinto an oil phase and a fluosulfonic; acidfphase, andIrecovering from said lubricating, oil phase a lubricating oi1.of improved viscosity, index as aproduct of the process.- I

PAUL

Number Name 1,950,878 Burk Mar. `13,l 1934;? 2,375,675 v Matuszak May 8,19455 2,378,762 Freyy June 19, 1945 v2,428,753 Linn. 001:.7. 1947" 

1. A PROCESS FOR REFINING A LUBRICATING OIL TO IMPROVE ITS VISCOSITY INDEX, WHICH COMPRISES TREATING A LUBRICATING OIL WITH FLUOSULFONIC ACID IN THE PRESENCE OF A LOW-BOILING HYDROCARBON FOR A PERIOD OF ABOUT 15 TO ABOUT 120 MINUTES, AT A TEMPERTURE IN THE RANGE OF ABOUT 10 TO ABOUT 60* C. AND AT SUFFICIENT PRESSURE TO MAINTAIN LIQUID PHASE, USING A VOLUME RATIO OF SAID FLUO- 